Figure 15. Abney level. 



2. Beach Profile Surveys . 



Rows o£ pipes were established perpendicular to the coastline at each 

 site to determine elevation changes along the beach profile lines. The 

 pipe method of measuring beach profile changes has been used in a number 

 of studies (e.g., Inman and Rusnak, 1956; Harrison and Wagner, 1964; 

 Williamson, 1972) and is discussed by Urban and Galvin (1969). Two-inch- 

 diameter (5.1 centimeters) galvanized pipes were driven into the sand and 

 beach rock with a pneumatic jackhammer (Fig. 16; Gonzalez, 1970). Many 

 of the subaqueous (below MLW) pipes did not require the jackhammer tech- 

 nique, as sufficient sand cover existed for standard jetting installation. 



Two rows of pipes were driven at both Jupiter and Hollywood, and four 

 rows were driven at Boca Raton; each row was numbered from north to south. 

 Spacing between rows was approximately 250 feet at Jupiter and Hollywood, 

 and 250, 150, and 100 feet, from north to south at Boca Raton. The dis- 

 tance between adjacent pipes on the same profile line was approximately 

 28 feet (8.5 meters), with the exception of subaqueous pipes at Boca 

 Raton and Hollywood, where the spacing was approximately 50 feet. The 

 subaqueous pipes at Boca Raton were connected by a handline to facili- 

 tate the survey of that part of the profile by scuba-equipped divers 

 (Fig. 17). Figure 18 is a plan view of the completed profile installa- 

 tion at Boca Raton. 



Beach surface elevations relative to MSL were determined by measur- 

 ing the distance between the sand surface and a permanent reference mark 

 on each pipe. Elevations of the pipe reference marks were determined by 

 standard transit and stadia rod or hand level surveying techniques using 

 established bench marks in the vicinity (see Fig. 19) . 



With the exception of the subaqueous profile surveys at Boca Raton, 

 all data were recorded directly in a standard field notebook. Subaqueous 



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